Single-trip lateral coring systems and methods

ABSTRACT

A coring system may be used to create a lateral section or borehole off a wellbore, and obtain a core sample therefrom. The coring system may include a coring assembly connected to a deflector assembly to enable a single-trip coring operation. The coring assembly may include a coring bit and an outer barrel for extracting a core sample. A deflector of the deflector assembly may direct the coring bit to drill a lateral section in the borehole and extract a core sample therefrom. The coring assembly and deflector may include mating surfaces to collectively retrieve the deflector assembly and coring assembly in a single trip. A collar of the coring assembly may engage against a stop surface of a shoulder or sleeve of the deflector assembly. By pulling upwardly, the engaged collar may release the anchored deflector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and priority to, U.S. patentapplication Ser. No. 61/736,982, filed on Dec. 13, 2013 and entitled“SINGLE-TRIP LATERAL CORING SYSTEMS AND METHODS,” which application isincorporated herein by this reference in its entirety.

BACKGROUND

In order to determine the properties of a particular formation, a coresample may be extracted. For instance, a vertical wellbore may becreated in a formation. A column of rock or other materials found in theformation may be extracted as the wellbore is made, and then removedfrom the wellbore, after which a detailed study may be performed. Thedetailed study and analysis may yield information and identify thelithology of the formation. Other characteristics such as porosity andpermeability of the formation, the potential storage capacity and/orproduction potential for hydrocarbon-based fluids (e.g., oil and naturalgas), and the like may also be determined from the core sample.

Coring systems may attempt to extract the core sample in a state that,to the extent possible, closely resembles the natural state in which therock and other materials are found in the formation. For instance, acoring bit may be connected to a drill string and extended into awellbore. The coring bit may include a central opening and, as thecoring bit rotates and drills deeper into the formation, materials fromthe wellbore can enter through the central opening and form a column ofrock in the drill string. When the column has a desired length, thecolumn of rock may be retrieved and brought to the surface.

The column of rock forming the core sample may form directly within thedrill string, and then be returned to the surface by lifting the coringbit towards the surface. In other systems, a core barrel may be loweredthrough the central opening in the drill string. A column of rock canform in the core barrel, and the core barrel can be retrieved. Anothercore barrel may then be lowered through the drill string and used toobtain another core sample from the vertical section of the formation

SUMMARY OF THE DISCLOSURE

Assemblies, systems and methods of the present disclosure may relate toobtaining a core sample from a lateral section, or borehole, extendingfrom a wellbore. In one example system, a coring system is provided toextract a core sample in a single trip. The example coring system mayinclude a coring assembly that includes a coring bit attached to a corebarrel. The core barrel may include a collection cavity where a coresample may be collected. The coring assembly may be connected to adeflector used to deflect the coring assembly as it drills a lateralsection, ore borehole, and extracts the core sample. A releasableattachment between the coring assembly and the deflector may allowcollective run-in of the coring assembly and deflector into a wellbore,and later separation to allow the coring assembly to drill the lateralsection ore borehole and extract a coring sample.

In another implementation, a single-trip coring system may include acoring assembly having an outer core barrel coupled to a coring bit. Asacrificial element may connect the coring assembly to a deflectorassembly with a ramp face. An anchor assembly may be coupled to thedeflector assembly and may include expandable slips to engage a wall ofthe wellbore.

In another implementation, a method may be used to drill a lateralborehole and extract a core sample therefrom in a single trip. Themethod may include inserting a coring system into a wellbore within aformation, the coring system including a coring assembly coupled to adeflector assembly. The deflector assembly may be anchored within thewellbore and a coupling between the coring and deflector assemblies maybe released. A lateral borehole may be drilled using the coringassembly. Drilling the lateral wellbore may result in simultaneouslyobtaining a core sample from the formation. The core sample and aportion of the coring assembly may then be removed from the borehole.

This summary is provided solely to introduce some features and conceptsthat are further developed in the detailed description. Other featuresand aspects of the present disclosure will become apparent to thosepersons having ordinary skill in the art through consideration of theensuing description, the accompanying drawings, and the appended claims.This summary is therefore not intended to identify key or essentialfeatures of the claimed subject matter, nor is it intended to be used asan aid in limiting the scope of the claims.

BRIEF DESCRIPTION OF DRAWINGS

In order to describe various features and concepts of the presentdisclosure, a more particular description of certain subject matter willbe rendered by reference to specific embodiments which are illustratedin the appended drawings. Understanding that these drawings depictexample embodiments and are not to be considered to be limiting inscope, nor drawn to scale for each embodiment contemplated herein,various embodiments will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1 illustrates a partial cross-sectional view of an example systemfor extracting a core sample from a rock formation, according to oneembodiment of the present disclosure;

FIG. 2 illustrates an enlarged view of a coring assembly of the systemof FIG. 1, according to one embodiment of the present disclosure;

FIG. 3 illustrates another partial cross-sectional view of the system ofFIG. 1, the system being used to extract a lateral core sample deviatingfrom the primary wellbore, according to an embodiment of the presentdisclosure;

FIG. 4 illustrates a cross-sectional view of another coring system forextracting a lateral core sample, the coring system including a coringassembly and deflector assembly for one-trip setting of the deflectorand extraction of the core sample;

FIGS. 5 and 6 illustrate the coring system of FIG. 4, with the coringassembly deflected laterally to extract the lateral core sample,according to one embodiment of the present disclosure;

FIG. 7 illustrates the coring system of FIG. 4, with the coring assemblyretracted from a lateral section in accordance with an embodiment of thepresent disclosure;

FIG. 8 illustrates the coring system of FIG. 4, with the coring assemblyand deflector assembly collectively being removed from the wellboreaccording to an embodiment of the present disclosure;

FIGS. 9-11 illustrate cross-sectional views of another example of acoring system, in various stages of a method that includes inserting asingle-trip coring system, extracting a lateral core sample, andretrieving the coring system from the wellbore, in accordance with anexample embodiment of the present disclosure;

FIG. 12 illustrates a cross-sectional view of an example anchor assemblythat may be used in a coring system in accordance with some embodimentsof the present disclosure;

FIG. 13 illustrates a cross-sectional end view of the anchor assembly ofFIG. 12, taken along the plane 13-13 of FIG. 12; and

FIG. 14 illustrates an enlarged cross-sectional view of one embodimentof a locking subassembly of the anchor assembly of FIG. 12.

DETAILED DESCRIPTION

In accordance with some aspects of the present disclosure, embodimentsherein relate to systems and assemblies for extracting a core samplefrom a formation. More particularly, embodiments disclosed herein mayrelate to systems, assemblies and methods for extracting a core samplefrom a lateral section, borehole, or other deviated portion of awellbore. Further embodiments may also relate to extracting a coresample closely resembling the natural state of the formation, and of asize allowing for study and analysis, while minimizing or eliminatingcompaction, fracture, or other deformation of the core sample. Moreparticularly still, embodiments disclosed herein may relate tosingle-trip systems and assemblies for anchoring a deflector, extractinga core sample from a lateral section, and retrieving the deflector andcoring assembly.

Some principles and uses of the teachings of the present disclosure maybe better understood with reference to the accompanying description,figures and examples. It is to be understood that the details set forthherein and in the figures are presented as examples, and are notintended to be construed as limitations to the disclosure. Furthermore,it is to be understood that the present disclosure and embodimentsrelated thereto can be carried out or practiced in various ways and thataspects of the present disclosure can be implemented in embodimentsother than the ones outlined in the description below.

To facilitate an understanding of various aspects of the embodiments ofthe present disclosure, reference will be made to various figures andillustrations. In referring to the figures, relational terms such as,but not exclusively including, “bottom,” “below,” “top,” “above,”“back,” “front,” “left,” “right,” “rear,” “forward,” “up,” “down,”“horizontal,” “vertical,” “clockwise,” “counterclockwise,” “inside,”“outside,” and the like, may be used to describe various components,including their operation and/or illustrated position relative to one ormore other components. Relational terms do not indicate a particularorientation or position for each embodiment contemplated herein. Forexample, a component of an assembly that is “below” another componentwhile within a wellbore may be at a lower elevation while in a verticalportion of a wellbore, but may have a different orientation duringassembly, or when the assembly is in a lateral or deviated portion a theborehole, when outside of the borehole or wellbore, during manufacture,or at other times. Accordingly, relational descriptions are intendedsolely for convenience in facilitating reference to some embodimentsdescribed and illustrated herein, but such relational aspects may bereversed, rotated, moved in space, placed in a diagonal orientation orposition, placed horizontally or vertically, or similarly modified.

Relational terms may also be used to differentiate between similarcomponents; however, descriptions may also refer to certain componentsor elements using designations such as “first,” “second,” “third,” andthe like. Such language is also provided for differentiation purposes,and is not intended limit a component to a singular designation. Assuch, a component referenced in a description of a particular embodimentas the “first” component may be the same component that may bereferenced in the claims as a “second,” “third,” or other component.Furthermore, to the extent the description refers to “an additional” or“other” element, feature, aspect, component, or the like, it does notpreclude there being one such element, feature, aspect, component, orthe like in other embodiments. Where the claims or specification referto “a” or “an” element, such reference is to be inclusive of othercomponents and understood as “one or more” of the element. No component,feature, structure, or characteristic is to be considered as required oressential unless explicitly stated as such for each embodiment of thepresent disclosure.

Technical and scientific terms used herein are to have a meaning asunderstood by a person having ordinary skill in the art to whichembodiments of the present disclosure belong, unless otherwise defined.Embodiments of the present disclosure can be implemented in the testingor practice with methods and materials equivalent or similar to thosedescribed herein.

Referring now to FIG. 1, an example coring system 100 is illustrated.The coring system 100 of FIG. 1 may be inserted within a wellbore 102 ina formation 104, and used to extract a core sample of the formation 104.In some embodiments, the core sample extracted from the formation may becore sample removed from a lateral or deviated perforation of thewellbore 102, rather than from a vertical portion of the wellbore 102.

In the particular embodiment illustrated in FIG. 1, the coring system100 is shown as including a coring assembly 106, a deflector assembly108, and an anchor assembly 110, each of which are optionallyinterconnected. As discussed in greater detail herein, for instance, thecoring assembly 106 may be connected to the deflector assembly 108, andthe coring assembly 106, deflector assembly 108, and anchor assembly 110may collectively be inserted and run into the wellbore 102, and loweredto a desired position. When at the desired location, the anchor assembly110 may be secured in place. For instance, in this embodiment, theanchor assembly 110 includes an anchor 112 and expandable slips 114 thatmay engage the inner surface of the wellbore 102, although the anchorassembly 110 may include any suitable construction, and may be integralwith, or distinct from, the deflector assembly 108. A frictional orother engagement between the expandable slips 114 and the inner surfaceof the wellbore 102 may effectively hold the anchor 112 and thedeflector assembly 108 at a desired axial position, and potentially at adesired orientation, within the wellbore 102.

The coring assembly 106 may be separable from the deflector assembly 108in an embodiment in which the coring assembly 106 is connected to thedeflector assembly 108 and/or the anchor assembly 110. By way ofillustration, a selectively engageable latch or other mechanism may beused to selectively connect and/or disconnect the coring assembly 106relative to a deflector 116 of the deflector assembly 108. In otherembodiments, and as described in greater detail hereafter, a sacrificialelement may be used to connect the coring assembly 106 to the deflectorassembly 108. For instance, once the anchor assembly 110 is secured atan axial and/or rotational position within the wellbore 102, axialand/or rotational movement of the coring assembly 106 may be used tobreak a sacrificial element, thereby disconnecting the coring assembly106 from the deflector 116.

While the coring assembly 106, deflector assembly 108, and anchorassembly 110 may be collectively run into the wellbore 102 to allow asingle trip to insert, anchor, and use such assemblies, such anembodiment is merely illustrative. In other embodiments, for instance,the coring assembly 106 may be separate from the deflector assembly 108.In such an embodiment, the anchor assembly 110 may be anchored in place.Thereafter, the coring assembly 106 may be run into the wellbore 102. Ofcourse, the deflector assembly 108 may be run into the wellbore 102 andsecured in a desired position and orientation collectively with theanchor assembly 110, or run in and secured in place following insertionand/or anchoring of the anchor assembly 110.

Regardless of whether the coring assembly 106 is connected to the anchorassembly 110 and/or deflector assembly 108 to allow for single-tripextraction of a core sample, the coring assembly 106 may use thedeflector assembly 108 to extract a core sample from the wellbore 102,and potentially a deviated or lateral section of the wellbore 102 asdiscussed hereafter. For instance, as shown in FIG. 1 and as betterviewed in the enlarged view of FIG. 2, the coring assembly 106 mayinclude a coring bit 118 for drilling into the formation 104 andextracting a core sample therefrom. The coring bit 118 may be connectedto an outer barrel 120 (e.g., using threaded connector 122), and coresamples may collect within the coring bit 118 and/or the outer barrel120.

In particular, the coring bit 118 may include an opening 124 in a distalend thereof, which opening 124 may be in communication with a collectionchamber 126 within the coring bit 118 and/or the outer barrel 120. Thecoring bit 118 and the outer barrel 120 may be connected to a drill rig(not shown) that can rotate the coring bit 118, optionally by alsorotating the outer barrel 120 and/or a drill string (not shown) attachedto the outer barrel 120. As one or more cutters 128 on the coring bit118 cut into the formation 104, materials from the formation may collectwithin the collection chamber 126 to form a columnar core sample. Whenthe coring bit 118 has cut deep enough to fill the collection chamber126, or otherwise obtain a sample for study, the core sample can beremoved. To remove the core sample, the entire coring assembly 106 couldbe withdrawn from the wellbore 102.

In another embodiment, however, a core sample may be obtained andremoved without corresponding removal of the coring assembly 106. Forinstance, in this particular embodiment, an inner barrel 130 may belocated within the collection chamber 126. The inner barrel 130 may beselectively removable and can include an interior opening which may alsoact as a collection chamber. As shown in FIGS. 1 and 2, for instance, aretrieval wire 132 may be connected to an upper end of the inner barrel130. When the core sample is desired, the inner barrel 130 may belowered into the coring assembly 106. The core barrel 130 may be locatedat any desired position, including adjacent the distal end of the coringbit 118. As the coring bit 118 then drills the wellbore 102, or cuts alateral section into the wellbore 102, the core sample may collectinside the collection chamber of the inner barrel 130. When the innerbarrel 130 is filled or otherwise has a core sample of a desired size,an operator may use the retrieval wire 132 to remove the inner barrel130 and extract the core sample. If additional core samples are desired,the inner barrel 130 (or a different inner barrel 130) may be loweredtowards the coring bit 118, and drilling may continue until another coresample is obtained.

A core sample collected within the collection chamber 126 of the outerbarrel 120 or the inner barrel 130 may have any suitable size and shape.For instance, as discussed herein, a length of the collected core samplemay vary from a few inches to many hundreds of feet. The width of thecore sample may also vary. For instance, the opening 124 and collectionchamber 126 (or the interior of the inner barrel 130) may have a widthfrom about one inch (25 mm) to about four inches (102 mm). In a moreparticular embodiment, the inner barrel 130 and/or outer barrel 120 maycollect a core sample having a width greater than two inches (51 mm),which can facilitate measuring porosity of the formation 104. Of course,in other embodiments, the core sample may have a width or diameter lessthan one inch (25 mm) or greater than four inches (102 mm). Moreover,while the core sample may have a circular cross-sectional shape in someembodiments, the outer barrel 120 and/or inner barrel 130 may in otherembodiments facilitate collection of a columnar core sample having asquare, elliptical, trapezoidal, or other cross-sectional shape.

The coring assembly 106 may include any number of additional or othercomponents. For instance, the inner barrel 130 and collection chamber126 may be illustrated in FIGS. 1 and 2 somewhat schematically. In someembodiments, the inner barrel 130 and/or collection chamber 126 mayinclude fasteners to secure the inner barrel 130 in place within theouter barrel 120 and/or the coring bit 118. Such fasteners may beselectively engageable and disengageable to allow removal of the innerbarrel 130 independent of the outer barrel 120 or the coring assembly106.

As also seen in FIG. 2, an example coring assembly 106 may also includeone or more hydraulic lines 134, 136. In this particular embodiment,fluid may be pumped through a channel 138 in the outer barrel 120, anddirected towards the coring bit 118. The channel 138 of this embodimentis shown as surrounding the collection chamber 126; however, in otherembodiments the channel 138 may be otherwise located or omittedentirely. As fluid is sent through the channel 138, it may pass into oneor more hydraulic lines 134 within the coring bit 118 or outer barrel120. Such fluid may then be used as a cutting fluid to facilitatecutting by the coring bit 118.

In another embodiment, fluid passing through the hydraulic line 134and/or the channel 138 may be used for additional or other purposes. Forinstance, the embodiment shown in FIG. 2 illustrates an additionalhydraulic line 136 outside of the coring bit 118. The illustratedhydraulic line 136 is shown as extending to the deflector 116, but mayextend to any desired location, and can be used for any suitablepurposes. For instance, referring again to FIG. 1, the coring assembly106 may be connected directly or indirectly to an anchor assembly 110,and one or more expandable slips 114 may be selectively expanded orretracted using hydraulic fluid supplied by the hydraulic line 134. Whenexpanded, the expandable slips 114 may engage the wellbore 102 andanchor the deflector 116 in place. Thereafter, the coring assembly 106may be inserted into the wellbore 102, or detached from the deflector116, to begin a coring process.

More particularly, as noted above, some embodiments of the presentdisclosure relate to using the coring assembly 106 to extract a coresample from a lateral section or perforation of the wellbore 102.Turning now to FIG. 3, the example coring system 100 of FIG. 1 is shownin additional detail, while extracting a lateral core sample.

In general, the deflector 116 may be used to deflect the coring assembly106 laterally to create a deviated or lateral section 103 in thewellbore 102. As the deflection occurs, the coring assembly 106 maydrill laterally into the formation 104 and extract a core sample fromthe lateral section 103 of the wellbore 102, as opposed to a vertical orother primary section of the wellbore 102. In FIGS. 1 and 3 forinstance, the deflector 116 is shown as being generally wedge-shaped,and having a ramp face 140. The particular incline of the ramp face 140may be varied in any number of manners. For instance, relative to thelongitudinal axis of the vertical portion of the wellbore 102, the rampface 140 may extend at an angle between about 1° and about 10°, althoughsuch an embodiment is merely illustrative. In a more particularembodiment, the angle may be between about 2° and about 6°. In stillanother example embodiment, the angle of the ramp face 140 may be about3°. Of course, in other embodiments, the ramp face 140 may be inclinedat an angle less than about 1° or more than about 10°.

Further, while the ramp face 140 may have a single segment extending ata constant incline, in other embodiments the ramp face 140 may havemultiple segments. In this particular embodiment, for instance, the rampface 140 is shown as including at least two segments, each with adifferent degree of incline. In other embodiments, however, the rampface 140 may include three or more segments, any or each of which mayhave a different incline relative to other segments.

As the coring assembly 106 is detached from the deflector 116, or wheninserted into the borehole following anchoring of the anchor assembly110 and the deflector assembly 108, the coring bit 118 may come intocontact with the ramp face 140. Because of the angle on the ramp face140, further downward movement of the coring assembly 106 may cause thecoring bit 118 to travel across the ramp face 140, and gradually movetowards the sidewall of the wellbore 102. The coring bit 118 mayoptionally rotate as it moves along the ramp face 140 and/or as itengages the sidewall of the wellbore 102. Using cutting elements, thecoring bit 118 may then cut laterally into the wellbore 102 and form thelateral section 103.

As discussed herein, when the coring bit 118 forms the lateral section103 of the borehole, rock and other materials of the formation 104 maypass through an opening 124 in the coring bit 118 and collect within thecollection chamber 126 and/or an inner barrel 130. Ultimately, once acore sample of a desired size has been collected (e.g., when the innerbarrel 130 is filled or near filled), the core sample may be extracted.Extraction of the core sample may occur with or without removal of thecoring assembly 106, as discussed herein.

One aspect of a coring system 100 of the present disclosure maytherefore include the ability to extract a core sample from a deviatedportion of a borehole, with such sample having any desired length.Indeed, in some embodiments, a core sample extracted using the coringsystem 100 may extend many hundreds of feet (e.g., 1000 feet, 2000 feet,or more) into the lateral section 103 of the wellbore 102. In otherembodiments however, the core sample may be much shorter (e.g., lessthan 1000 feet in some embodiments, less than 100 feet in otherembodiments, and less than 50 feet in still other embodiments). As anexample, if an operator of the coring system 100 wishes to obtain asample of the formation three feet (0.9 m) away from the wellbore 102,as measured in a direction perpendicular to the wellbore 102, and thelateral section 103 extends at a constant angle of 3° relative to thelongitudinal axis of the wellbore 102, a core sample of about sixty feet(18.3 m) should provide the desired information. Of course, if angle ofthe lateral section 103 is greater or smaller than 3°, or varies alongits length, or if the desired information is nearer or further from theprimary portion of the wellbore 102, the length of the core sample mayvary. Further, while the illustrated wellbore 102 is shown as vertical,a wellbore may not be vertical; however, the coring system 100 may beused to drill a lateral, deviated section, or borehole, off of even anon-vertical wellbore to obtain a core sample.

While some formations may have relatively constant properties over largedistances, other formations may show large deviations over even shortdistances. Accordingly, by extending the coring assembly 106 laterallyfrom the primary portion of the wellbore 102, a core sample maytherefore be obtained to capture formation properties further from themain wellbore 102. Gradients and other changes in properties maytherefore be analyzed and determined. Further, because core samples maybe of virtually any continuous length, core samples may be relativelyunfractured and large enough to allow for simplified analysis. Furtherstill, as continuous core samples are obtained through a coring bit 118,the coring system 100 may operate with few or no explosives that couldotherwise create fractured or compacted core samples.

While a core sample may be obtained over a lateral section 103 thatextends a relatively short distance from the primary portion of thewellbore 102, the length may be much larger as noted above. Indeed, thelateral section 103 may extend for potentially hundreds of feet asdiscussed herein. Optionally, to facilitate lateral drilling of thelateral section 103, the coring assembly 106 may use directionaldrilling equipment. While not shown in FIGS. 1-3, such directionaldrilling equipment may include steerable drilling assemblies thatinclude a bent angle housing to direct the angle of drilling duringdrilling of the lateral section 103. The directional drilling equipmentmay employ other directional control systems including, but not limitedto, rotary steerable systems. Example rotary steerable systems mayinclude hydraulically controlled pads, deflecting rods, or a variety ofother features and components used to push, point, or otherwise controla drilling direction.

As discussed above, some aspects of the present disclosure furtherrelate to a coring system that allows a core sample to be taken in adeviated portion of a borehole, while also using a single trip to anchorthe deflection assembly and obtain the core sample. Some systems mayalso allow detachment and retrieval of the deflection assembly in thesame, single trip. Turning now to FIGS. 4-8, an example single-tripcoring system 200 is illustrated in greater detail. In particular FIGS.4-8 illustrate various steps in an example method that may be used torun the coring system in a wellbore 202, drill a lateral section of awellbore 202, obtain a core sample, and remove the coring assemblyand/or deflector assembly. The single-trip coring system 200 may sharevarious features with the coring system 100 of FIGS. 1-3. To avoidobscuring aspects of the embodiment in FIGS. 4-8, redundant features maynot be described again in detail, but it should be appreciated by aperson having ordinary skill in the art that the various features ofFIGS. 1-3 (e.g., an anchor assembly having expandable slips, an innerbarrel, hydraulic lines and channels, etc.) may be incorporated into theembodiments of FIGS. 4-8.

More particularly, FIG. 4 illustrates a single-trip coring system 200that may include a coring assembly 206 connected to a deflector assembly208 in accordance with some embodiments of the present disclosure. Inthis particular embodiment, the coring assembly 206 and deflectorassembly 208 may be connected in a manner that allows the coringassembly 206 to be run into the wellbore 202 at the same time as thedeflector assembly 208.

The coring assembly 206 and deflector assembly 208 may be placed in thewellbore 202, and lowered to a desired location. The deflector assembly208 may include a deflector 216 with a ramp face 240. When the ramp face240 is oriented in a direction corresponding to a desired trajectory fora lateral section of the wellbore 202, the deflector assembly 208 can beanchored in place. Following anchoring of the deflector assembly 208,the coring assembly 206 can be separated from the deflector assembly 208and moved along the length of the ramp face 240 to create the lateralsection or borehole off the wellbore 202, and to take a core sample.

In the particular embodiment shown in FIG. 4, a sacrificial element 242may connect the coring assembly 206 to the deflector assembly 208. Theillustrated sacrificial element 242 may extend between the deflector 216and a shaft of the coring bit 218 and/or outer barrel 220, but may haveany suitable configuration. In operation, the sacrificial element 242may be designed to break or fail when a sufficient load is placedthereon. For instance, once the deflector 216 is anchored in place, anaxial load may be placed on the outer barrel 220 of the coring assembly206 (e.g., by loading a drill string). The anchored deflector 216 may beconfigured to have a higher resistance to an axial load that thesacrificial element 242, such that when the load exceeds the maximumforce allowed by the sacrificial element 242, the sacrificial element242 may break but the deflector 216 may remain anchored in place.

In another embodiment, the coring assembly 206 may rotate to break thesacrificial element 242. By way of illustration, the coring bit 218and/or outer barrel 220 of the coring assembly 206 may be configured torotate to drill a lateral section of the wellbore 202. In thisembodiment, the coring bit 218 may be integrated with the outer barrel220, and the sacrificial element 242 may break when the rotational forceis applied to the outer barrel 220 (e.g., by a surface rig). Regardlessof whether the sacrificial element 242 breaks as a result of axialloading, rotation of the coring assembly 206, or in some other manner,the coring assembly 206 may break free from the deflector assembly 208and be allowed to move axially along the wellbore 202.

The sacrificial element 242 may take any number of different forms. InFIG. 4, for instance, the sacrificial element 242 may be a shear screwor break bolt configured to fail when a load is applied to translate orrotate the coring assembly 206 relative to the deflector assembly 208(e.g., when the deflector assembly 208 is anchored). In otherembodiments, the sacrificial element 242 may include a notched tabconfigured to break where stress concentrations form at notches. Instill other embodiments, other sacrificial elements or non-sacrificialelements may be used. Thus, the sacrificial element 242 may be replacedby other structures, such as a selectively engageable latch that allowsselective disconnection and/or reattachment of the coring assembly 206relative to the deflector assembly 208, without breaking a connector.

Once the sacrificial element 242 is broken, an operator of the coringsystem 200 may move the coring assembly 206 downwardly, further into thewellbore 202. Upon doing so, the coring assembly 206 may move along aramp face 240 of the deflector system 208, and can be directed againstthe interior surface of the wellbore 202. The coring bit 218 can rotateor otherwise be used to cut into the formation 204 and create a lateralsection of the wellbore 202. As shown in FIGS. 5 and 6, the coring bit218 may progressively cut a lateral section 203 that deviates laterallyrelative to a primary or other portion of the wellbore 202.

As the coring bit 218 cuts into the formation 204 and forms the lateralsection 203 of the wellbore 202, the coring bit 218 may extract samplesof the formation 204. In this particular embodiment, the coring bit 218and the outer barrel 220 of the coring assembly 206 define a collectionchamber 226 that is accessible through an opening 224 in the distal endof the coring bit 218. A core sample may therefore collect in thecollection chamber 226 for removal either with the coring assembly 206,or independent from removal of the coring assembly 206 (e.g., using aninner barrel). Multiple core samples may also be obtained withoutremoving the coring assembly 206 as discussed in greater detail withrespect to FIGS. 1-3. Both the outer barrel 220 and an inner barrel maybe examples of core barrels usable in connection with coring systems ofthe present disclosure.

When the desired core samples have been obtained, an operator of thecoring system 200 may remove the coring assembly 206. As shown in FIG.7, for instance, the coring assembly 206 may be removed from the lateralsection 203 of the wellbore 202 by pulling upwardly on the outer barrel220 and the coring bit 218.

In the embodiment shown in FIGS. 4-7, removal of the coring assembly 206may also be used to remove the deflector assembly 208. For instance, asshown in FIG. 7, the coring bit 218 and/or outer barrel 220 may include,or be connected to, a collar 244 that extends radially outward from theouter barrel 220. The deflector assembly 202 may, in turn, include or beattached to a sleeve 246. In the illustrated embodiment, the sleeve 246of the deflector assembly 208 is shown as defining an opening orpassageway through which the outer barrel 220 of the coring assembly 216may pass. The size of the opening may be such that the inner diameter ofthe opening allows the outer diameter of the outer barrel 220 to beslideably received thereby. The inner diameter of the opening may,however, be smaller than the outer diameter of the collar 244. As aresult, when the coring assembly 206 is pulled back, the collar 244 mayengage the lower surface 248 of the sleeve 246, which lower surface 248may act as a stop surface by restricting the collar 244 from movingupwardly past the lower surface 248. To move the coring assembly 206upwardly, the deflector assembly 208 may therefore also be un-anchoredand released from engagement with the wellbore 202. In embodiments inwhich the deflector assembly 208 is anchored in place, the deflectorassembly 208 may be released in any number of manners. A more particulardiscussion of one manner for releasing the anchored deflector assembly208 is discussed in additional detail with respect to FIGS. 12-14. FIG.8 illustrates the coring assembly 206 moving upwardly and carrying thedeflector assembly 208, as the anchored position of the deflectorassembly 208 is illustrated in phantom lines.

The sleeve 246 of the deflector assembly 208, and the collar 244 of thecoring assembly 206, may be formed or constructed in any number ofmanners. For instance, the sleeve 246 may be integrally formed with thedeflector 216. In another embodiment, such as that shown in FIGS. 4-8,the sleeve 246 may be mechanically fastened to the deflector 216. Inthis particular embodiment, a fastener 250 (e.g., a bolt, screw, pin,rivet, or other mechanical fastener, or some combination thereof) may beused to secure the sleeve 246 within a recess 252 in the deflector 216.When secured in place, the sleeve 246 is optionally secured to restrict,and potentially prevent, axial and/or rotational movement of the sleeve246 along the wellbore 202. Thus, while the coring assembly 206 may moveaxially and/or rotationally within the wellbore 202, the sleeve 246 mayremain static. In a similar manner, the collar 244 may be integrallyformed, or distinct from, the coring bit 218 and/or the outer sleeve220. Optionally, the collar 244 may rotate with the drill bit 218,although in other embodiments, the collar 244 may include a bearing orother component to allow rotation of the coring bit 218 independent ofthe collar 244.

In embodiments in which the sleeve 246 is static and the coring assembly206 passes through the sleeve 246, the sleeve 246 may also be a bearing,or may include one or more bearings or bearing surfaces. For instance,the sleeve 246 may include one or more bearings or bushings to reducefriction as the coring assembly 206 moves axially within the opening inthe sleeve 246 or to reduce friction as a result of the coring assembly206 rotating within the opening in the sleeve 246. An example bearingthat may be included as part of the sleeve 246, or connected thereto,may include a thrust bearing, roller bearing, spherical bearing, orother bearing, or some combination thereof. In an example embodimentusing a spherical bearing, the bearing may allow angular deflection ofthe outer barrel 220 while the outer barrel 220 and coring bit 218travel along the ramp face 240 of the deflector assembly 208 to drill alateral section into the wellbore 202. A spherical bearing may also beused to support axial, sliding motion of the outer barrel 220 as coringassembly 206 moves in an upwardly or downwardly directed path.

The fastener 250 used to connect the sleeve 246 to the deflector 216 mayalso have additional or other properties or structures. For instance,rather than a mechanical fastener, the sleeve 246 may be secured inplace using other mechanisms, including mechanical attachments such aswelding, adhesives, thermal bonding, threaded connectors, and the like.Regardless of the particular type of attachment used to connect thesleeve 246 to the deflector 216, the attachment may have a greaterstructural strength when compared to the sacrificial element 242. In oneembodiment, a greater structural strength of the fastener 250 or othermechanical attachment may be used to allow the sacrificial element 242to break prior to failure of the fastener 250, to ensure that the coringassembly 206 can break free of the deflector 216, and remain guided bythe fixed sleeve 246.

Another aspect of the present disclosure, as shown in FIGS. 7 and 8,includes for extracting a core sample by creating a lateral section 203of the wellbore 202, while not creating a separate bore. When two boresare present, governmental regulations may provide for abandonmentprocedures to be performed separately on each bore, thereby increasingthe cost and decreasing the efficiency in abandoning a well. However, aseparate bore is not created, but rather the bore is merely widened, asingle abandonment procedure may be performed. In particular, incomparing FIGS. 7 and 8, while a lateral section 203 may be created, thelateral section 203 may act as a perforation of the primary portion ofthe wellbore 202. Rocks or other materials of the formation 204 may bepositioned between the lateral section 203 or borehole and the primarywellbore (see FIG. 7), but may wash out to connect the distal end of thelateral section 203 with the primary portion of the wellbore 202 (seeFIG. 8). Washing out the lateral section 203 may be particularly likelywhen the length of the lateral section 203, or the maximum lateraloffset from the vertical portion of the wellbore 202, is relativelyshort. Removing the coring assembly 206 in such embodiments may alsofacilitate wash outs such that the lateral section 203 or borehole maymerely be a widened portion of the wellbore 202, rather than a separatebore or well. A wash out may also be particularly likely when thewellbore 202 is an uncased or openhole wellbore as shown in FIGS. 4-8,although in other embodiments a cased wellbore may be used.

Turning now to FIGS. 9-11, another embodiment of a coring system 300 isshown in additional detail. In particular, FIGS. 9-11 illustrate variouselements of a method for anchoring a deflection assembly 308 andextracting a core sample in a single trip. Retrieval of the deflectionassembly 308 may also include release of the deflection assembly 308 insome embodiments.

In general, the coring system 300 of FIGS. 9-11 may be relativelysimilar to the coring system 200 of FIGS. 4-8. For instance, the coringsystem 300 may include a coring assembly 306 that is connected to thedeflection assembly 308 using a sacrificial element 342 or some otherreleasable connector. When inserting the coring assembly 306 and thedeflection assembly 308 into the wellbore 302 formed in the formation304, the sacrificial element 342 may be in an engaged or unbroken statethat maintains the relative position of the coring assembly 306 relativeto the deflection assembly 308. By selectively disengaging a releasableconnector, or by causing the sacrificial element 342 to fail (e.g.,using axial motion following anchoring of the deflector assembly 308, orby rotating a coring bit 318 of the coring assembly 306), the coringassembly 306 may move axially along the wellbore 302 while the deflector316 remains anchored in place.

In the particular embodiment shown in FIGS. 9-11, the coring assembly306 may include a coring bit 318 that can be mechanically attached to anouter barrel 320. In particular, this embodiment illustrates a threadedconnector 322 between the coring bit 318 and the outer barrel 320. Usingthe threaded connector 322, the coring bit 318 may be selectivelyattached, removed, replaced, and the like. In other embodiments, thecoring it 318 may be integrally formed with the outer barrel 320, or maybe attached to the outer barrel 320 or a drill string (not shown) inother manners.

In general, the coring bit 318 may act in a manner similar to othercoring bits described herein. In FIG. 9, for instance, the coring bit318 is shown as including an opening 324 in the distal end thereof, andwhich facilitates the collection of a core sample. For instance, as thecoring bit 318 drills laterally into the formation 304 (see FIG. 10),materials from the formation 304 may enter the opening 324 and collectwithin a collection chamber. An optional inner barrel (not shown) mayalso be provided to allow extraction of core samples without removal ofthe coring assembly 306, and/or collection of multiple, different coresamples in a single trip of the coring assembly 306, whether collectedalong a single lateral section 303 or at multiple lateral sections.

In FIG. 9, the illustrated coring assembly 306 is shown as including acollar 344 connected to the coring bit 318 and/or the outer barrel 320.In particular, the illustrated collar 344 may include an interioropening into which the outer diameter of an upper portion of the coringbit 318 may be positioned. Optionally, the collar 344 has a fixed axialposition along the coring assembly 306. Thus, once the coring assembly306 is detached from the deflector assembly 308, the collar 344 may movealong the deflector 316 along with the coring bit 318. While theillustrated embodiment illustrates the collar 344 positioned around thecoring bit 318, in other embodiments the collar 344 may be secured to,or may encompass, a portion of the outer barrel 320.

The collar 344 may be used to guide the coring bit 318 in accordancewith some embodiments of the present disclosure. In this particularembodiment, for instance, the deflector 316 of the deflector assembly308 may include a track 340 for interfacing with the collar 344. Theshape, size, and configuration of the track 340 may match that of thecollar 344. For instance, the track 340 may have a concave surface witha contour to match an outer contour of the collar 344. In anotherembodiment, the track 340 may include a rail, guide, or other similarcomponent that may correspond to the collar 344 and/or facilitatemovement of the collar 344 along the track 340.

As the collar 344 moves downwardly and laterally along the track 340,the coring bit 318 may also move. The track 340 may be inclined relativeto the longitudinal axis of the wellbore 302, thereby causing the coringbit 318 to ultimately engage a sidewall of the wellbore 302. By rotatingthe coring bit 318, the coring bit 318 can also cut into the sidewall ata trajectory corresponding to the configuration of the track 340. Asshown in FIG. 10, for instance, the track 340 may guide the coring bit318 as it creates a lateral section 303 of the wellbore 302. Of course,as the lateral section 303 is created, a core sample of the lateralsection of the formation 304 may also be formed within the collectionchamber 326 of the coring assembly 306.

Once the desired core samples are obtained, the coring assembly 306 maybe removed as shown in FIG. 11. In particular, the outer barrel 320 maybe connected to a drill string, and can be pulled upwardly. As the outerbarrel 320 is pulled upwardly, the coring bit 318 may move out of thelateral section 303 of the wellbore 302, and towards an upper portion ofthe deflector assembly 308. In this particular embodiment, the upperportion of the deflector assembly defines a shoulder 346. Moreparticularly, the coring bit 318 and the collar 344 may follow the track340. The track 340 may direct the collar 344 of the coring assembly 306against the shoulder 346, which can act as a stop surface to restrictthe collar 344 from moving upwardly past the shoulder 346. The shoulder346 may be sized so that the distance between the shoulder 246 and thesidewall of the wellbore 302 defines a passageway with sufficient sizeto allow the outer barrel 326 to slideably move therebetween. The collar344 may, however, have an increased radial size, and may not fit in thepassageway between the shoulder 346 and the sidewall of the wellbore302. As a result, the collar 344 may engage the shoulder 346, which canrestrict, and potentially prevent, the collar 344 from moving past theshoulder 346.

When pulling upwardly on the outer barrel 326, the coring assembly 306may be used to retrieve the deflector assembly 308 from the wellbore302. For instance, as discussed herein, the deflector assembly 308 maybe selectively released from its anchored position within the wellbore302. Following un-anchoring of the deflector assembly 308 (e.g., byreleasing an anchor assembly connected to the deflector assembly 308),an upwardly-directed force on the coring assembly 306 may also cause thedeflector assembly 308 to move upwardly by virtue of the engagementbetween the collar 344 and the shoulder 346.

The collar 344 of the embodiment shown in FIGS. 9-11 may have a numberof different constructions. In one embodiment, for instance, the collar344 may be integrally formed with the coring bit 318 and/or outer barrel320, and may rotate with the coring bit 318 when it rotates and digs thelateral section 303 of the wellbore 302. In the illustrated embodiment,however, the collar 344 may also be separately formed and then attachedto the coring assembly 306. The interior opening of the collar 344 mayhave a size sufficient to allow the coring bit 318 to be positionedtherein. Optionally, the coring bit 318 may float within the collar 344.For instance, the collar 344 may be configured not to rotate with thecoring bit 318. One or more bearings or other components may be used tofacilitate rotation of the coring bit 318 within the collar 344. In oneembodiment, the collar 344 includes a groove, notch or other structurethat mates with a corresponding structure of the track 340. As a result,as the coring assembly 306 moves along the track 340, the drill bit 318may rotate while the track 340 may restrict rotation of the collar 344.

As should be appreciated by a person having ordinary skill in the art inview of the disclosure herein, some embodiments of the presentdisclosure may relate to apparatus, systems, and methods for anchoring adeflector and extracting a core sample in a single trip. In accordancewith some of those embodiments, the deflector may also be anchored andthereafter un-anchored to allow setting and retrieval in the same,single trip.

An example anchor assembly 410 that may be used in connection withembodiments of the present disclosure is shown in additional detail inFIGS. 12-14. This particular anchor assembly includes an anchor body 412and one or more expandable slips 414. More particularly, as described ingreater detail below, hydraulic fluid passing through the anchor body412 may be used to selectively expand the expandable slips 414, whichmay then engage the exterior wall around a wellbore.

FIGS. 12-14 depict the example embodiment of an anchor assembly 410,with various operational positions. In one embodiment, the anchorassembly 410 may be used, for example, in combination with a coringassembly and a deflector assembly for extracting a core sample from alateral section, or borehole of a wellbore, or from some other lateralsection or borehole (e.g., a deviation portion from an already deviatedborehole). It should be appreciated, however, that the anchor assembly410 may be used in many different types of downhole assemblies, and thatcoring assemblies and/or deflector assemblies are not exhaustiverepresentations of the assemblies or components with which the anchorassembly 410 may be used. For instance, the anchor assembly 410 may beused in any drilling assembly using an anchoring tool, including with awhipstock for a sidetracking process. Further, it is to be fullyrecognized that the different teachings of the embodiments disclosedherein may be employed separately or in any suitable combination toproduce desired results.

FIGS. 12-14 provide an operational overview of the anchor assembly 410.In particular, the anchor assembly 410 may be lowered into an uncasedwellbore in a locked and collapsed position shown in FIGS. 12 and 13.When the anchor assembly 410 reaches a desired depth, the anchorassembly 410 may be unlocked and expanded to a set position shown inphantom lines in FIGS. 12 and 13, where expandable slips 414 of theanchor assembly 410 may engage a surrounding open wellbore wall, or acasing. The anchor assembly 410 may be configured to expand over a rangeof diameters, and FIGS. 12 and 13 depict the anchor assembly 410, withthe maximum expanded configuration shown in phantom lines. Finally, toremove the anchor assembly 410 from the well, the anchor assembly 410may be released from the casing to return to an unlocked and collapsedposition as shown in FIG. 12.

The anchor assembly 410 may generally comprise a top sub 454 connectedvia threads 456 to a generally cylindrical mandrel 457 having a fluidchannel 466 therethrough, which in turn is connected via threads 456 toa nose 458. In one embodiment, the anchor assembly 410 may include anupper box connection 460 and a lower pin connection 462 for connectingthe anchor assembly 410 into a downhole assembly. The upper boxconnection 460 may be connected to the lower end of a deflector assembly408, for example. Optionally, a pipe plug 464 may be connected to thenose 458 to close off a fluid channel 466 of the mandrel 457 so that theanchor assembly 410 may be expanded hydraulically.

The mandrel 457 may be the innermost component within the anchorassembly 410. Disposed around and slidingly engaging the mandrel 457 isa spring stack 468 in the illustrated embodiment, along with an upperslip housing 470, one or more slips 414, and lower slip housing 472. Oneor more recesses 474 may be formed in the slip housings 470, 472 toaccommodate the radial movement of the one or more slips 414. Therecesses 474 may include angled channels formed into the wall thereof,and these channels may provide a drive mechanism for the slips 414 tomove radially outwardly into the expanded positions depicted in phantomlines in FIGS. 12 and 13. In one embodiment, the anchor assembly 410 maycomprise three slips 414 as shown in FIG. 13, wherein the three slips414 may be spaced at 120° intervals circumferentially around the anchorassembly 410, and in the same radial plane. It should be appreciated,however, that any number of slips 414 may be disposed in the same radialplane around the anchor assembly 410. For example, the anchor assembly410 may comprise four slips 414, each approximately 90° from each other,two slips 414, each approximately 180° from each other, or any number ofslips 414. Further, while the slips 414 may be offset at equal angularintervals, other embodiments contemplate such offsets being varied. Forinstance, when three slips 414 are used, the one slip 414 may be spacedabout 90° from one slip 414 and about 135° from another slip 414.

In the embodiment shown in FIG. 12, a piston housing 476 may beconnected to the lower slip housing 472 (e.g., using threads). Thepiston housing 476 may form a fluid chamber 478 around the mandrel 457within which a piston 480 and a locking subassembly 482 may be disposed.The piston 480 may connect to the mandrel 457 (e.g., using threads), andthe mandrel 457 may include ports 484 that enable fluid flow from theflowbore 466 into the fluid chamber 478 to actuate the anchor assembly410 to the expanded position shown in phantom lines in FIGS. 12 and 13.In one embodiment, a seal may be provided between the piston 480 and themandrel 457, between the piston 480 and the piston housing 476, and/orbetween the piston housing 476 and the lower slip housing 472.

FIG. 14 depicts an enlarged view of the locking subassembly 482, shownreleasably coupled to the piston housing 476 via one or more shearscrews 486. The locking subassembly 482 shown in FIG. 14 may include alock housing 488 mounted about the mandrel 457, and a lock nut 490,which interacts with the mandrel 457 to prevent release of the anchorassembly 410 when pressure is released. The outer radial surface ofmandrel 457 may include serrations which cooperate with inverseserrations formed on the inner surface of locking nut 490, as describedin more detail below.

Referring now to FIGS. 12 and 13, the anchor assembly 410 is illustratedwith the slips 414 in a retracted position which allows the anchorassembly 410 to be inserted into a wellbore. When the slips 414 areexpanded to the position illustrated in phantom lines in FIGS. 12 and13, the slips 414 may be in an expanded position, in which the slips 414extend radially outwardly into gripping engagement with a surroundingopen wellbore wall or casing. The anchor assembly 410 may have twooperational positions within a particular wellbore—namely a collapsedposition as shown in FIGS. 12 and 13 for running the anchor into awellbore, and an expanded position as shown in phantom lines in FIGS. 12and 13, for grippingly engaging a wellbore.

To actuate the anchor assembly 410, hydraulic forces may be applied tocause the slips 414 to expand radially outwardly from the locked andcollapsed position of FIGS. 12 and 13 to the unlocked and expandedposition shown in phantom lines. Specifically, fluid may flow down thefluid channel 466 and through the ports 484 in the mandrel 457 into thechamber 478 surrounded by the piston housing 476. When the anchorassembly 410 is the lowermost tool in a drilling, coring, or othersystem, the pipe plug 464 may be used to close off the fluid channel 466through the mandrel 457 to allow fluid pressure to build up within theanchor assembly 410 to actuate it (e.g., by radially expanding the slips414 of the anchor assembly 410). If, however, another tool is run belowthe anchor assembly 410, the pipe plug 464 may be removed so thathydraulic fluid can flow through the anchor assembly 410 to the lowertool. In such an operation, the lower tool could include a similar pipeplug so that hydraulic pressure can be built up in both the lower tooland the anchor assembly 410 to actuate both tools.

Pressure may continue to build in the fluid chamber 478 as the piston480 provides a seal therein until the pressure is sufficient to causeshear screws 492 to shear. Since the piston 480 may be connected to themandrel 457, the piston 480 may remain stationary while the outer pistonhousing 476 and the lower slip housing 472 connected thereto may moveaxially upwardly from the position shown in FIG. 12. Upward movement ofthe lower slip housing 472 can act against the slips 414 to drive theslips 414 radially outwardly along the channels 494. This upward motionmay also cause the slips 414 and the upper slip housing 470 to moveaxially upwardly against the force of the spring stack 468, which isoptionally a Belleville spring stack.

Because the outer piston housing 476 may be moveable to expand the slips414 rather than the piston 480, the anchor assembly 410 design may notuse a redundant piston stroke, and the anchor assembly 410 may maintainapproximately the same axial length in the collapsed position of FIG. 12and in the expanded position. The anchor assembly 410 may also have ashorter mandrel 457 as compared to other anchors, and the slips 414 maybe nearly unidirectional. Therefore, the spring stack 468 can act as ameans to store up energy. If the spring stack 468 were not present, theenergy stored in the anchor assembly 410 could be based on how much themandrel 457 stretches as the slips 414 are set against a wall of thewellbore. Although the mandrel 457 is made of a hard metal, such assteel, it still stretches a small amount, acting as a very stiff spring.Therefore, in order to store up energy in the anchor assembly 410, thisspring effect may be weakened or unstiffened to some degree, such as byadding the spring stack 468. In so doing, the stroke length for settingthe slips 414 may be increased.

The anchor assembly 410 may also be configured for operation withinwellbores having a range of diameters. In an embodiment, a spacer screw496 may be provided to maintain a space between the lower slip housing472 and the upper slip housing 470 when the anchor assembly 410 is inits maximum expanded position. During assembly of the anchor assembly410, when installing the slips 414, the upper slip housing 470 and thelower slip housing 472 may be abutted against each other, and extensionsin the slips 414 may be aligned with the channels 494 in the recesses474 of the slip housings 470, 472. Then the upper and lower sliphousings 470, 472 may be pulled apart and the slips 414 can collapseinto the anchor assembly 410 around the mandrel 457. To guard againstthe anchor assembly 410 overstroking downhole, the spacer screw 496 canrestrict the upper and lower slip housing 470, 472 from abuttingtogether as during assembly, thereby restricting the slips 414 fromfalling out of the anchor assembly 410. Thus, in the maximum expandedposition, the spacer screw 496 may provide a stop surface against whichthe lower slip housing 472 may be restricted, and potentially prevented,from further upward movement so that it remains spaced apart from theupper slip housing 470. The spacer screw 496 can be provided as a safetymechanism because the slips 414 should engage the wellbore wall in anintermediate expanded position, well before the lower slip housing 472engages the spacer screw 496.

Thus, the anchor assembly 410 may be fully operational over a wide rangeof diameters, and can have an expanded position that varies depending onthe diameter of the wellbore. As such, the anchor assembly 410 may bespecifically designed to provide proper anchoring of a coring, drilling,or other assembly to withstand compression, tension, and torque for arange of wellbore diameters. Specifically, the anchor assembly 410 isconfigured to expand up to at least 1.5 times the collapsed diameter ofthe anchor assembly 410. For example, in one embodiment, the anchorassembly 410 has a collapsed diameter of approximately 8.2 inches (208mm) and is designed to expand into engagement with an 8½ inch (216 mm)diameter wellbore up to a 12¼ inch (311 mm) diameter wellbore. Where theanchor assembly 410 is used in a cased wellbore, an anchor assembly 410having a diameter of approximately 8.2 inches (208 mm) may correspondgenerally to a 9⅝ inch (244 mm) casing up to 13⅜ inch (340 mm) casing.

Once the slips 414 are expanded into gripping engagement with awellbore, to prevent the anchor assembly 410 from returning to acollapsed position until so desired, the anchor assembly 410 may includea locking subassembly 482. As the piston housing 476 moves, so too may alock housing 488 that is connected thereto via shear screws 486 mountedabout the mandrel 457. As shown in FIG. 14, the lock housing 488 maycooperate with a lock nut 490, which can interact with the mandrel 457to restrict or prevent release of the anchor assembly 410 when hydraulicfluid pressure is released. Specifically, the outer radial surface ofmandrel 457 may include one or more serrations which cooperate withinverse serrations formed on the inner surface of the locking nut 490.Thus, as the piston housing 476 moves the lock housing 488 upwardly, thelocking nut 490 can also move upwardly in conjunction therewith, causingthe serrations of the locking nut 490 to move over the serrations of themandrel 457. The serrations on the mandrel 457 may be one-way serrationsthat allow the locking nut 490 and the components that are connectedthereto to move upstream when hydraulic pressure is applied to theanchor assembly 410. Therefore, because of the ramped shape of theserrations, the locking nut 490 may be permitted to move in onedirection, namely upstream, with respect to the mandrel 457. Theinteracting serrations can restrict or prevent movement in thedownstream direction since there may be no ramp on the mandrelserrations that angle in that direction. Thus, interacting edges of theserrations can facilitate movement in a single direction, therebyrestricting the anchor assembly 410 from returning to a collapsedposition until so desired.

In an embodiment, the locking nut 490 may be machined as a hoop and thensplit into multiple segments. A spring 498 (e.g., a garter spring) maybe provided to hold the segments of the locking nut 490 around themandrel 457. The spring 498 may resemble an O-ring, except that thespring 498 can be made out of wire. Such wire may be looped around thelocking nut 490, and the ends can be hooked together. The spring 498 mayallow the sections of the locking nut 490 to open and close as thelocking nut 490 jumps over each individual serration as it movesupwardly on the mandrel 457. Thus, the spring 498 may allow the lockingnut 490 to slide up the ramp of a mandrel serration and jump over to thenext serration, thereby ratcheting itself up the mandrel 457. The spring498 can also hold the locking nut 490 segments together so that thelocking nut 490 cannot back up over the serrations on the mandrel 457.

The anchor assembly 410 may also designed to return from an expandedposition to a released, collapsed position. For instance, as discussedherein with respect to the coring systems 100, 200, and 300, someembodiments of a coring system contemplate a system in which an anchormay be set (e.g., expanded), a core sample extracted, the anchorreleased (e.g., retracted), and a coring assembly and anchor retrieved,within a single trip. The anchor assembly 410 may therefore be used insuch embodiments to allow the anchor to be released, which may allowanother component, such as a deflector assembly, to be released andretrieved.

The anchor assembly 410 of FIGS. 12-14 can be released from grippingengagement with a surrounding wellbore wall by applying an upwardlydirected force sufficient to allow the slips 414 to retract to thereleased and collapsed position shown in FIG. 12. In particular, thelock housing 488 shown in FIG. 14 may be connected to the piston housing476 by shear screws 486. To return the anchor assembly 410 to acollapsed position, an axial force can be applied to the anchor assembly410 sufficient to shear the shear screws 486, thereby releasing thelocking subassembly 482. As shown in FIG. 12, a release ring 499 may bedisposed between the upper slip housing 470 and the mandrel 457. In oneaspect, the release ring 499 can provide a shoulder to restrict theupper slip housing 470 from sliding too far downwardly with respect tothe slips 414 in the run-in, retracted position of FIG. 12, or afterreleasing the anchor assembly 410 to the position shown in FIG. 12. Inanother aspect the release ring 499 may be configured to allow themandrel 457 to move a small distance axially before the slips 414disengage from the wellbore to allow for the shear screws 486 to shearcompletely. Thus, when an axial force is applied to the mandrel 457, therelease ring 499 can allow for the slips 414 to maintain engagement withthe wellbore to provide a counter force against which the shear screws486 can shear. Therefore, the release ring 499 can allow the shearscrews 486 to shear completely, which enables the slips 414 to collapseback into the anchor assembly 410. With the anchor assembly 410 in thereleased and collapsed position of FIG. 12, the anchor assembly 410 canbe removed from the wellbore.

In accordance with one embodiment, the anchor assembly 410 of FIGS.12-14 may be used in connection with a coring system 200 of FIGS. 4-8 ora coring system 300 of FIGS. 9-11. It should be appreciated in view ofthe disclosure herein, that when connected to the anchor assembly 410, acoring system 200, 300 may be used to expand and engage the slips 414against a wellbore and anchor a corresponding deflector assembly 208,308 in place. Optional hydraulic lines (see FIG. 2) may be used toprovide hydraulic fluid to expand the slips 414.

When a core sample has been obtained, the anchor assembly 410 may bereleased by applying an upwardly directed force to retract the slips 414as discussed herein. For instance, as shown in FIGS. 4-8, a collar 244of a coring assembly 206 may engage a sleeve 246 of a deflector assembly208. By pulling upwardly on the coring assembly 206, a correspondingupward force can be applied to the deflector assembly, which may also beconnected to the mandrel 447 of the anchor assembly 410. Such upwardforce, if sufficient to shear the shear screws 486, may allow the slips414 to retract, thereby allowing the coring assembly 206, deflectorassembly 208, and anchor assembly 410 to be removed. A similar processmay be used with the coring system 300 of FIGS. 9-11, in which a collar344 or a coring assembly 306 may engage a shoulder 346 of a deflectorassembly 308 to exert an upward force that may release the slips 414 ofthe anchor assembly 410.

Accordingly, the various embodiments disclosed herein include componentsand structures that are interchangeable, and may be combined to obtainany number of aspects of the present disclosure. For instance, in asingle trip, a deflector may be anchored in place, a core sampleextracted, the deflector released, and the deflector and coring assemblyremoved. In the same or other embodiments, the coring system maypotentially be used at multiple locations along a wellbore. Forinstance, the deflector and coring assembly may be lowered to a desiredlocation and anchored in place. The coring assembly may then be used toextract a core sample, and the deflector can be released. The coringassembly and deflector may then be raised or lowered to anotherlocation, where the process is repeated by anchoring the deflector,extracting a core sample, and potentially releasing the anchoreddeflector. Such a process may be repeated multiple times to obtain coresamples at multiple vertical locations, and within a single trip.

To facilitate obtaining core samples at multiple locations in a singletrip, the anchor assembly 410 may be modified in a number of differentmanners. For instance, a motor, power source, and wireless transpondermay be provided. The motor may mechanically move the slips 414 and/orthe mandrel 457 to allow selective expansion and retraction of the slips414. Thus, the shear screws 486 are optional, and multiple engagementsmay occur along a length of a wellbore.

Although only a few example implementations have been described indetail above, those skilled in the art will readily appreciate that manymodifications are possible in the example implementation withoutmaterially departing from the disclosure of “Singe-Trip Lateral CoringSystems and Methods.” Accordingly, any such modifications are intendedto be included in the scope of this disclosure. Likewise, while thedisclosure herein contains many specifics, these specifics should not beconstrued as limiting the scope of the disclosure or of any of theappended claims, but merely as providing information pertinent to one ormore specific implementations that may fall within the scope of thedisclosure and the appended claims. Any described features from thevarious implementations disclosed may be employed in combination. Inaddition, other implementations of the present disclosure may also bedevised which lie within the scopes of the disclosure and the appendedclaims. Additions, deletions and modifications to the implementationsthat fall within the meaning and scopes of the claims are to be embracedby the claims.

In the claims, means-plus-function clauses are intended to cover thestructures described herein as performing the recited function and notonly structural equivalents, but also equivalent structures. Thus,although a nail and a screw may not be structural equivalents in that anail employs a cylindrical surface to secure wooden parts together,whereas a screw employs a helical surface, in the environment offastening wooden parts, a nail and a screw may be equivalent structures.It is the express intention of the applicant not to invoke 35 U.S.C.§112, paragraph 6 for any limitations of any of the claims herein,except for those in which the claim expressly uses the words ‘means for’together with an associated function.

Certain implementations and features may have been described using a setof numerical upper limits and a set of numerical lower limits. It shouldbe appreciated that ranges including the combination of any two values,e.g., the combination of any lower value with any upper value, thecombination of any two lower values, and/or the combination of any twoupper values are contemplated unless otherwise indicated. Certain lowerlimits, upper limits and ranges may appear in one or more claims below.Numerical values are “about” or “approximately” the indicated value, andtake into account experimental error and variations that would beexpected by a person having ordinary skill in the art.

What is claimed is:
 1. A single-trip coring system, comprising: a coringassembly including a core barrel for capturing a core sample, and acoring bit coupled to the core barrel; a deflector for deflecting thecoring assembly into a formation for drilling a lateral section of aborehole; and a releasable attachment between the coring assembly andthe deflector.
 2. The single-trip coring system recited in claim 1, thereleasable attachment including a sacrificial element.
 3. Thesingle-trip coring system recited in claim 1, the core barrel includinga collection chamber and one or more of: an outer core barrel; or aninner core barrel.
 4. The single-trip coring system recited in claim 1,further comprising: an expandable anchor coupled to the deflector. 5.The single-trip coring system recited in claim 1, further comprising: acollar coupled to the coring bit; and a sleeve coupled to the deflector,the sleeve including an interior chamber through which the core barrelextends, the interior chamber being sized to restrict movement of thecollar through the interior chamber.
 6. The single-trip coring systemrecited in claim 5, the collar being configured to move with the coringbit, and the sleeve being configured to remain stationary while thecoring bit moves following release of the releasable attachment.
 7. Thesingle-trip coring system recited in claim 1, the core barrel beingrotatable within the sleeve.
 8. The single-trip coring system recited inclaim 1, further comprising: a collar connected to the coring bit; and ashoulder connected to the deflector, the shoulder being sized to createa passageway with a sidewall of a wellbore, the passageway permittingthe core barrel to extend therethrough while restricting movement of thecollar therethrough.
 9. The single-trip coring system recited in claim8, the shoulder being configured to remain stationary relative to thesleeve, while the collar is configured to move axially with the coringbit.
 10. The single-trip coring system recited in claim 9, the corebarrel being configured to be rotatable within the collar.
 11. Thesingle-trip coring system recited in claim 8, the deflector including atrack for mating with the collar.
 12. A method for single-trip drillingof a lateral borehole and extracting a core sample therefrom,comprising: inserting a coring system into a wellbore within aformation, the coring system including a coring assembly coupled to adeflector assembly; anchoring the deflector assembly within thewellbore; releasing a coupling between the coring assembly and thedeflector assembly; drilling a lateral borehole using the coringassembly while simultaneously obtaining a core sample from theformation; and removing the core sample and at least a portion of thecoring assembly from the borehole.
 13. The method recited in claim 12,further comprising: un-anchoring the deflector assembly within theborehole; and collectively removing the deflector assembly and coringassembly from the borehole following obtaining of the core sample fromthe formation.
 14. The method recited in claim 13, the method furthercomprising: obtaining at least one additional core sample through thelateral borehole, prior to removing the deflector assembly and coringassembly from the borehole.
 15. The method recited in claim 13, whereincollectively removing the deflector assembly and coring assemblyincludes: retracting a the coring assembly from the lateral borehole;engaging a collar of the coring assembly against a stop surface of thedeflector assembly; and pulling upwardly on the coring assembly andthereby un-anchoring the deflector assembly.
 16. The method recited inclaim 12, wherein obtaining the core sample from the borehole includesobtaining a core sample having a size and construction sufficient todetermine porosity.
 17. The method recited in claim 12, whereinanchoring the deflector assembly includes anchoring the deflectorassembly at a first location within the wellbore, the method furthercomprising: un-anchoring the deflector at the first location within thewellbore; anchoring the deflector at a second location within thewellbore; obtaining at least one additional core sample at an additionallateral borehole corresponding to the second location within thewellbore; and removing the at least one additional core sample from thewellbore.
 18. The method recited in claim 12, wherein drilling thelateral borehole includes obtaining a continuous core sample along alength of the lateral wellbore.
 19. A single-trip coring system,comprising: a coring assembly including an outer core barrel coupled toa coring bit; a deflector assembly having a ramp face; a sacrificialelement coupling the coring assembly to the deflector assembly; and ananchor assembly coupled to the deflector assembly, the anchor assemblyincluding a plurality of expandable slips.
 20. The single-trip coringsystem recited in claim 19, wherein: the coring assembly includes acollar coupled to the coring bit, the collar being configured to moveaxially with the coring bit upon selective release by the sacrificialelement; and the deflector assembly includes a stop surface forretrieving the deflector assembly by engaging the collar and restrictingpassage of the collar upwardly past the stop surface.